SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e167f1e14fd5e47d194a8c6d9c93bb17c42cf5f5bfb8902c0f2661327591a63e' 
  AND token = 'bNaSXLXkzG5tJ1Q1zqHnQANhO1lRLKO8Ra55CA+faB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}